Wind box sealing construction for sintering machines



March 4, 1-958 v I ow 2,825,550

WIND BOX SEALING CONSTRUCTION FOR SINTERING MACHINES Filed Dec. 6, 1955 4 Sheets-Shee t 1 mmvrom 1 Fig I HAROLD E. ROWEN BY I f V g z March 4, 1958 H. E. ROWEN 2,825,550

WIND BOX SEALING CONSTRUCTION FOR SINTERING MACHINES Filed Dec. 6, 1955 4 Sheets-Sheet 5 "i I .m "7w Fig.

I II Fig. 8 Fig. 9

I INVENTOR. Fig; 10 HAROLD E. ROWEN- March 1953 H. E. ROWEN 2,825,

WIND BOX SEALING CONSTRUCTION FOR SINTERING MACHINES Filed Dec. 6, 1955 4 Sheets-Sheet 4 1144x020 5R0 mm; BY J L -,5 727- 4% United States Patent- WIND The present invention relates to improvements in means for forming connections between an upper wind box or hood and a lower wind box ofa sintering machine, so arranged as to permit the pallets and wheel assemblies to travel in a path between the hood and wind box.

Machines of this character are used not only for sintering of ore concentrates and the like, but have many analogous uses including calcining, pellet burning, heat treating, roasting etc. For convenience, it is referred to as a sintering machine.

More particularly, my invention relates to an improvement upon and addition to the construction shown, described and claimed-in my prior patent application, Serial No. 484,095, filed January 26, 1955, entitled, Wind Box Seal for Sintering Machines. In that application as in the'present one, the general object was to provide a simple, efticient durabl'e means for preventing leakage and loss of air'or gas pressure or suction at the relatively moving closure elements forming the seal between the pallets and 'the adjacent edges of'the upper. hood and of thewind box and along the supports for the pallets.

a In my'prior application above identified, the general 7 object attained by the structure there disclosed was the provision of an effective seal which was not exposed to undue heat, which maintained its efiectiveness in prolonged use, and in which the hood or upper wind box rested upon moving pallet seal bars with a controlled reduced pressure on the bars, substantially less than the weight of the hood structure. Alternatively, increased pressure on the pallet seal bars could be provided, if desired; l

The present sealing apparatus may be considered to b designed for use on sintering machines such as the Dwight-Lloyd type. In the use of such apparatus, the structure disclosed in my prior application, above identified, may, under some conditions of operation, require an additional provision for more eflectively preventing ingress or egress of air or gases at thecoactin g sealing surfaces which lie between the upper and lower seal bars-of the pallets.

In carrying out the present invention, I provide a closed tunnel-like chamber coextensive with the longitudinal extent of the wind box and hood sealing means. This chamber or tunnel forms an additional enclosure embracing the longitudinally extending sealing means and pallet supporting wheels, and in which tunnel-like space, air or gas movement into or from the end portions is prevented while permitting the wheels to pass into and from them. By this arrangement, I am enabled to create either positive or negative air or gas pressure within the sealing chamber, to any degree having the desired relation to that obtaining within the tunnellike sealing chamber,

For simplicity, this chamber is frequently hereinafter referred to only as a tunnel.

' 'ljhe tunnel may be keptunder pressure or vacuum as 2,825,550 P ge? iterf .195?

2 required to control objectionable leakage, or it may be filled with selected gases. I Stated another way, an important objective is to provide a substantially gas or airtight connection-between the upper and lower wind boxes, which permits the pal lets and their wheel assemblies to-travel along the machine between the wind boxes without loss of {either positive or negative pressure of the air or'gases being used.

Preferred embodiments of my present invention, constituting additions to and improvements upon'previous sealing means used in the Dwight-Lloyd type of sintering machines, and particularly such sealing means as'a're closed in my aforementioned prior application, are illustrated in the accompanying drawings,in which:

Fig. 1 is a vertical section througha sintering machine, taken on 'a'plane transverse to'the path of 'the pallets and showing a portion of a hood or upper wind box; the lower wind box with my connecting sealing means, and also showing the pallets and trackways therefor; Fig. 2 is a transverse section on a somewhat enlarged scale illustrating in detail the tunnel at one side of the machine surrounding the pallet wheels, and showing the connections to the lower box structure and the closure connections with the upper box or hood;

Fig. 3 is a similar transverse section illustrating a wheel-embracing passage and closure means at'the entrance to or exit from the sealing tunnel;

Fig. 4 is a side elevation of the tunnel and entrance sealing wheel-embracing portion;

Fig. 5 is a longitudinal section of the tunnel entrance showing a modification of the wheel engaging and seat irig means;

Fig. 6 is a sectional view of an adjustable hood supporting structure and modified form of tunnel seal;

Fig. 7 is a fragmentary side elevation showing a portion of the upper and lower wind boxes and pallets pass-- ing therebetwecn with the pallet Wheels moving into the sealing tunnel; and

Figs. 8, 9 and 10 are detail sections illustrating modifications of the tunnel structure; T

Fig. 11 is a fragmentary sectional view similar to Fig. 2, showing a modification of the tunnel-forming structure in which the upper seal is formed at theupper edges of the pallet side walls; Y

Fig. l2'is a further modification of this tunnel arrangement with"coacting sliding seal bars at the top' of the pallet side walls;

Fig. 13 is a similar view showing a modification of the upper hood wind box and in which the top wall of the tunnel is in the nature of a slopings eal-shield extending inside the pallet side walls; and i Fig. 14 is a composite view of asection through a pallet, tunnels at each side and connecting passages to upper and lower wind boxes.

The cross section view of Fig, 1 illustrates the frame and traveling pallets of a sintering machine such as that to which my invention may be particularly well adapted.

One embodiment of my invention is illustrated in Figs. 1 to 4. The traveling pallets or receptacles designated 11! are adapted to move inend-to-end relation along a hor i zontal path, supported (except as will hereinafter appear) by their wheels 11 on rails 12. The rails are, in turn, carried by a frame structure designated generally 15, aiid which includes suitable vertical and herizemai structural members.

Rails 16, appearing in Fig. 1, provide a lower reach or return path for the pallets. The arrangement and func tion of the structure comprising the present inventioniis concerned only with the sealing means along the p atfiof the p let n h h t ey mo e 1' eflec ing ii c i ii limited. to. the. pallet return:

rib's forming supporting and guiding the sintei'ing operation. ..While it is customary in such machines to. provide for returning these'pallets 7 along a lower reach beneath thesintering path it is to be understood that other methods may be used fortransporting the'pallets from the end ofithe active or sintering path to starting position or drivingiendhat the'beginning Of-"this path. Accordingly, my present inventiodis'not v p structure, as Twill clearly appearfrom the following description; 7 i v q :Below the sintering path of the pallets, a lower wind box,1 designated 20, is here shown as having its side plates secured to and supported by longitudinally extending frame members 22 having upwardly extending flanges 23 onto which are fitted sealing elements as] 'will be;de-.

scribed.- 'The upperwind box or hood, only partially shown, mayhave its side wall portions 25 supported'ouF side for the grate member's to'structural parts of the frame;

1 7; Both the hood and lowerwind box are connected with coacting relatively sliding bars for the purpose of efiecting a seal at the sides of'the pallets; Various forms of such arrangements have ,been' used heretofore, but idifficulties have-been encountered'in eifectively sealing and negative pressures within the wind boxes.

Some of the former difiiculties have been overcome by the constructiondisclosedin my aforementioned prior application; Inasmuch as that structure lends itself to theiadapta'tion of the improvements of'the present inven-' tion, the drawings hereof include the related featuresiof that earlier application. "It is to be understood, however, that'van'ous forms of sealing devices betweenwind boxes gand movingsintering grate pallets may be effectively sup- =plemented, and their operation greatly improved, by my present invention. It follows that the presentinvention Q is not intended ftov be limited to any precise form of seal-i ing means between the pellets and wind boxes. Th'e'supplementaltunnel'sealing and pressure maintenance. of the J present'invention -may;be' used with a lower-wind box,

- with a hood or upper 'windbox, or, as in. the embodiments herein illustrated, may connectrand' cooperate with both of them} 7 In the apparatus herein shown, the pallets 10 comprise transverse horizontal grates, and' theusual material retaining side walls 26, outside of which are longitudinal side hub'carrying members. i V e ,Between the 'frameflanges 23, which ;are connected with the upper portions of the side walls of the lower Wind the positive surfaces and 'wheel assure:

used in the operation of the apparatus by leakage of air into thehood or wind box.

Again, as indicated 'above,-the present invention provides a means outside of the sealingbar and slidingstrip l connections, and outside of the pallet wheels whichmay' form a gas-tight connection between the hoodand lower wind box. .Such a tunnel-like housingextends .alongithe longitudinal distance of the upperand'lower'wind boxes and preferably somewhat beyond them at itslends r The particular sealing'means betweenthe pallets" and thewind boxes may "be of any suitable construction.

However, for the purposes of the present invention, some such sealingmeans are used'to assure that the processing tered, or otherwise treated;

i From inspection of'l ig.

air or gas streams pass through the material beingsin- 2, it will appear that ing plate 41 and the sealing. bars and wear strips torrn the top and one side'of asealingtunnel; The other verti f 7 cal .side and bottom of the tunnel may; befo'rrned'ofa.

longitudinally extending, plate" having .a vertical T portion 50 extending downwardly; from thegside plate, ofthe i hood, and then inwardly asat. 55. The'inner'edgeofFthe i plate 55 may extend beneath the seal'bar '37 between-it and the adjustable angle bar.35.""Suflicient flexibility;v of the materialofthe plate-portion 50 and 55. p'ermitsithe I vertical adjustment of 'theflowerseal barand supporting angle member '35 It will be s'eenthat this;

of the hood to the. sealing means connected withthe side plate 20 of the lower path of thewheels. i

wind box. a.

box 20, and the palletsiarevertically adjustablelongiv tudinalangle bar members 35. Vertical adjustment of these barsmay be efiected by adjusting screws indicated f at 36, it being assumed that the angle bars'3 5 are secured V by bolts or screws extending through elongated or en} larged openings. a 1

Carried by the longitudinal members are seal bars 37 having wear strips 38 on their upperfaces, coacting with V similar .wear fstrips 39 carried by the pallets. Similar .wear'st'rips on the pallets and seal bars 40,'extending the length of the jhood may effect ajsliding seal as'doi the' strips 38 an d 39. e

Secured to and receives a downtJJmed-flange 44 on the edge of the plate 41; f'pl rtethus spans and closesthe'space between the hood wall251and-theseal bar 40. v T

- 'The arrangement just described in connectioniwith 'Eig..2'corresponds to one form disclosed inrmy aforesaid 'prior. appnesa a; However, as, indicated in'the foregoing objects, itrs desirable to provide further assuranceagainst p leakageeither tolorfroin'the windboxes, for exaniplegto 5. Z a PK. 7 7 Q or roast anjy leakage of injurious' gases incidentto sin tering ing processes, or to prevent anmian'er gases being 7 extending laterally from the bar 40 ,is a connector plate 41q:extending the full lengthof the hood andjlaterally to a flanged angle member 43 having. 1 r

' longitudinally extending groove in theupper side ofiaii inwardly projecting" flange portion thereof. This groove;

' would occur at theendsfofthetunnel. Accordingly l 'provideaclos'ure r'neans at the ends of the tunnel coact i ing with the wheelslli'so that they may:move' intoand 7o fiowor any appreciable leak V V The' wear strips between the pallet and the seal bar 37 'aresuitably lubricated, preferably :bya lubricant p ie beriforms a 'ght sealing closureiconn'ection extending from thelside'plates wind box while surrounding the metering and supplyingmeans such as described innmyf aforesaid prior application. a q I The component parts of the tunnel assemblysjustfdc scribed may be of metal, heat resistant, woven materials,

or other compounded materials whichiihave sufiicient i flexibility to allow thesmall,relativelyvertical.movements for adjusting the. wear strips'38. and'39; .i

It will be-seen that the portions 50;and 5550f tun 'riel form-, in ettect, extensionsof the side plates 'of the hood outside of and below the wheels, i'whereby an; "ef-j fective' non-sliding seal is completed between thejhood 'and the lower windbox Thus',:forrexarnple, assuming 7 that the ends'of thetunnel are closed, if air'o'r gasispass ing' upwardly through the grates under either positivei:

or negative pressure, there wouldbeno leakage between 1 7 V the top of the lower 'wind boxr-and the bottom of the l -ho'od. Pa'ssage'of air or gaslin the downwarddirection likewise is assured.tobe"entirely through the'lgratesjbyi reason of the top tunnel plate rnembers l and: sliding wind'box. 7:: V "Obviously, unless 'prevent'edg considerable"'leakage out of the tunnel while free age isprecluded; i r

J In the forms shown seal connections between the grates and the;hood andg 1 l -i Br d he en. piertions of the tunnel are eachfitted with afllongitudinally j metal, and having a longi tudinal: passage therethro'ugh' 'e nsi c k i9s'-- mm e ifwiilre rably e open at one side and shaped, as indicated at .61, to conform to the contour of the flanged wheels 11 and their hubs.

Yieldable or flexible packing material may be fitted above and below the member 60, as indicated at 62 and 63. The resiliency of this sealing packing permits limited relative movement between the sealing strips and the member 61. At 64 (Fig. 4) are indicated openings for screws for holding the member 60 against longitudinal displacement while permitting a slight vertical adjustment.

As shown in this cross-sectional Fig. 3, the rails 12 are omitted within the tunnel, although obviously the liner member and packing may be fitted around the rails if it were found desirable to extend them through the tunnel space. The length of the liner member 60 is such that it will always embrace two or more pallet wheels, as indicated in the side elevation, thus further inhibiting any leakage or flow past the wheels, which obviously must not fit too closely in the space formed in the member 60 and through which they pass.

Other means for sealing the ends of the tunnel'may be used, such, for example, as may constitute divided flexible flaps 65, Fig. 5, extending inwardly from the top and bottom walls, arranged in pairs and spaced apart longitudinally, and normally meeting at their edges as in? dicated at 65A, except when flexed by passing of the wheel 11 therebetweeu.

To further efiect a substantially perfect control or balance of positive or negative pressure as between the interior' of the tunnel and the wind boxes, I may provide one or more pipe connections intermediate of its end clossures, as indicated at 68, leading to a suitable fan or blower, not shown, which may either draw air or gas fromithe tunnel, or pump air or gas into it to balance the pressures at the pallets and between the upper and lower hoods. A smaller pipe 69 may lead to thespace 61in each of the end closures 60. A'positive pressure or a negative pressure, as may be suited to theconditions withinithe'hood and wind box, may be thus maintained within the tunnel.

From the foregoing it will be seen that I have provid'edalongitudinally extending sealing chamber bridging the normal sealing means for either of one or both of the upper and lower wind boxes, and in which chamber a positive or negative air or gas pressure having the desired relation to concurrent pressures within the wind box or hood may be maintained; Thus," the sintering or analogous operation of the apparatus is' 'rnos'tefiectively protected against air or gas leakage.

1n the tunnel structure so far described, the sealing hood was assumed to be rigidly'flxed to the frame. Howevea'a's is disclosed in my prior application," the weight of the hood may be partially carried on thesealbars and may be adjustably' balanced to relieve the pressure" and consequent friction and wear on'the relatively'movable sealing strips. 1 In-Fig. 6 I have illustrated a tunnel structure attached to a hood mounting and supporting structure corresponding to that shown in my priorapplication.

Referring to the structure shown in Fig. 6, it will be noted that the upper seal bar 40 is attached to an ofiset ortZ b ar 7b, sealed to and rigid with a longitudinallower channel structure 80 fitted to'the lower edge ofthe side plate 25 of the hood. Fixed on ,thechannelSD are laterally extending bracket arms 81 through" which avertical rod 85 is passed, and which is slidable through a bracket 57 fixed to a vertical member of the frame of the machine. A spring 83 is so'mounted as to have its tension adjusted to control the amount of weight permitted to be taken by the seal bars and its wear strips, as the pallets move along them. i

The offset connecting member 70 permits the hood side walls tobe spaced away from the heat and direct flames in the material carried by the pe lets. The lowe i ld box is he wnv a h ng its uppe ed att ched to an angle strip on"which the'lower seal bai"'"37 :is carried. 1

The tunnel of Fig. 6 may comprise a substantially rectangular member having its' inturned horizontal walls 91 and 92 secured to the seal bar 40 and angle strip 75 in an airtight manner, as by welding,fo r example.

It is to' be understood that in the constructing and assembling of all such'parts,l do not wish to be limited to the manner of securing'them together, whether by bolts, welding, or otherwise. 7

It will be seen that the shape and size of the substantially rectangular tunnel, the inner side of which is formed by the pallet sealing bars and strips, is suchas to permit the free passage of the wheels therethrough', and its ends may be closed by members fitting the contour of the wheels and hubs, as-previously described.

If the rails are continued through the tunnel space, either the lower transverse wall forming member ofthe tunnel may be so positioned as to extend below rail supporting brackets 98, indicated in broken lines 55A in Fig, 2, or the rails may rest on the transverse portion 55 above these brackets, provision being made for desired flexibility of the inner edge of the transverse member 55. In practice, however, it is found unuecessary to extend the rails through the sealing tunnel.

It is desirable that the upper and lower sides of the tunnel and their points of attachment to the hood and wind box structure be self-supporting and yet be flexible to some extent, and in this connection it isobvious that various formations of the walls of the tunnel may be utilized. Such contours as that formed by the portions 50 and 55, for example, may be modified as indicated by the diagrammatic detail Figs. 8,9, and 10.

'In Fig-8 the plate93 is curved as shown; in Fig. 9 the plate 94 may have reverse bends; and in Fig. 10 a single offset 95 maylend the needed flexibility to the plate.

Obviously, many other formations may perform the functions essential to the objectives herein set forth. For example, modifications of tunnelstructures are further illustrated in Figs. 11 to 14, inclusive. The arrangement shown in Fig. 11 indicates a lower wind box 120, the C0111 nection to the seal bar corresponding somewhat to the arrangement of Fig. 2, there being an outwardly extending flange 122 and an upwardly extending flange 123,

shown as forming a part of an angle member, and to which another angle member is so bolted or secured as to be vertically adjustable by screws 13 6 corresponding to the screws36 of Fig. 2.

The pallet 16, wheels 11, and seal bar construction may be assumed to be'arranged as before. However, in lieu of the upper seal bar and wear strips arranged adjacent the wheel hubs of the pallets, the top seal plate of the l tunnel shown at 141 is secured to thesicle wall 125 of the hood, and projects inwardly and'is of such material and 7 thickness as to be somewhat flexible. A sealing contact bar is fixed to this plate and adapted to carry a sealing strip 139,,shown as set into a groove in the bar tee, and as having its lower edge contacting the outwardly turned flange portions formed on the side wall merribers of the pallets.

The vertical wall of the upper hood 125 extends down- A wardly and is suitably supported and securedas at 127 to a longitudinal structural member ofthe frame of the machine. The lower sealplate may be transversely adjustably secured to an angle bar fixed on the side plate member 125, while its other edge is in sealed contact with the flange of the angle member 135.

At 156 is indicated a cleaneout opening through the plate 155. Any desired number of such openings may be provided, each, of course, having a suitable closure. Access openingsfsuchasishown at-12 8,

r by an angle strip indicated'at 1 681" below the plate.

throughthe wall m'e'te'r' 125 and spaced at convenient intervals. V V P 4 Obviously, access openings through the side walld 'and clean-out openings through the bottom walls of the tunnels may be provided in all of the structures herein shown and described, being located Where needed, and,

{of cours'e, fitte d with removable closures,; which in all instances would be arranged to efiect a substantially'air tight seal when in closed position. 7

In Fig. l2 'a modification is illustrated inlwhich the wall of'thejwind box is in vertical alignment with the side wind box, and it, is understood that it is sealedthereto. r A seal bar 162 is fixed'to theinner' edge of the wall plate ifiti, whilerwear strip sections indicated at 7153 slidably; contact :the" seal bar 16 2 and are carried on the upper faces of flange portions of the pallet sidewalls;

A vertical plate ,165fexte nds, downwardly past the g the frame and connected tothe wind box, and having an onnected tof the lower wind box The adiustable mounting for the upper hood maybe provided. through connections, not shown. Suchsupport- V ingi rneans, connected with the hood, rnay'have adjusting o screws such as indicated as resting at 169 on a longitudinally extending member rigid with the frame 15.,

'walls 'of thel pallets. Thus, a modified form/of seal is t adopted; The structure shown inclndes'the top wall plate lfitl extending beneath a fiange at the lower edge of the the vertical walls at suitable positions.' v i 7. V

From'the foregoing description it"will be seen that in any and all of the several'modifications showml havepro-"i vided novel, inexpensive durable and efiectivemeans for f connecting the upper and lower windboxes'around. the

as required'for the operation of the machine. The air or gases may be brought toor from the upper 'side sof the pallets through a manifold-like conduit 19ilconnect'ed at 191 with tlieroof 192'of a hood having a downwardly V 7 extending portion19i 3 extending over one side of the path of the pallets to the outside of the wheelsilLand suitably connected'by a bottom seal piste structure indicated at 194. 7

The upper portion of this tunnel space be'clo se d by a vertical depending plate-like'member i9d secured to, the upper wall 192 and extending inside walls of the l V pallets 26a, and, of course, extending along a distance of a number of palletsdepending upon the length of;

the hood section.

I V Atfthe other side 'of "the path' of the pallets, a 'vertical', Wall 196 is connected with the lowerseal'bar .bya hori-a zontaliplate structure 191, while a top. plate'198 extends over the top of the adjacent side wall of the pallets,- and is provided witha downturned flange 199,asfshown. a 7 Access openings, such as12 3a, should be provided in path of the moving pallets; lnsth'e.constructionillustrated, for example,in Figs. 1 to 12, the tunnel is sealed with relation to the movinglpallets in a substantially air;

In Fig. 13 is shown an arrangement withan arched type of hood, the outer walls of which extend downwardly 1 outside of the wheels of the pallets ,Here, a vertical side wallpoi tion 178, mounted V on a jsupport'ing structure ic'arried by theiframe, andabove which and sealed thereto t isr an arched portion 1.71 extending longitudinally of the sintering path of the pallets, and instead of the upper sealing plates of the tunnel structure, such as 4101' 141,1

7 may use a shield in the nature of a sloping plate 175, secured' at its outer upper edge to thefhood ast a't 176 and extending inwardly and downwardly and provided V with a flange portion 178,wh'ich is positioned; to contact" -with, or at least extend; downwardly within, the upper inside edges of the side wsns ze of the pallets. .When

' rdesired,ithis flange 178'may carry ahe'at-resistant sealing strip, not shown: 1

7 j 'The imaten'al andrthicltness :ofjhe longitudinally ex? 1 tending sloping shield 175 is such that it 'maybersprung c or'bent slightly-to permit adjustment, bringing the'downturned flange 178 into thedesired close relationship to' the palletsside wallsi Such a slight change of angle 'lfected by' an adjusting means-comprising a rodlSl) extending loosely through an'openinfgain the plate, and havbf he pl er,-

ing a threaded portion receiving nuts 18 1 above and The lower seal plate 185 is preferably connected in fan tight rnanner to the wall and torthe' lower seal' bar 37,"

reflecting the seal for the lower wind box indicated at 20. v Thus, a substantially airtightjtunnelstructure is provided. An advantage of 'so positioning the seal-shield plate as toslope'sharply downwardly and inwardly toward the; a

V V pellets, is that of preventing accumulation 'offm'ater'ial on top of tbisslopingplate. 7 1 a 'In the composite arrangement of'Fig. l4, I have shown In this view the pallets 10a arelnar- 'adaptationsofthe tunnel "sealat opposite sides'of the 7 pallets and illustrative'connections' torthehoodia'nd lower or rn'ainwind box. 7 V

o row,-withrelativelyr high sidewalls 26a. f The lower windf box 29a'is shown as having a laterally extending pipe 2 152 E flforrleading' airv or gas toi' :9 .frromi 'the wind box, The

a seal, connections to e lowe wi d p l ma j p e p nd 1 r to those previously describ'edg and there may, of course;

'nally'exteuding tunnels; 7 Inallinstances, loose'and' floating particlesto f'material",

are 'prev'ente'dtrom coming into contact with the wheels andlowers'ealbars. j e 7 I i The seal bars and wearstrjips-prevent; shunting of air? of 'gases around .the sides of the pallets andgthus assure the passage of the air or gasesthrough the material on the grates r-of the'p'allets. jIhe sealing tunnehhaving its ends arranged to belclosed while permitting -the'pas sa'gn of the pallet wheels into and from the 'tunnelehar'tiber, v provides for establishing the'hcont'rolled or balancingpres-f sure within :the t el, most efi'ec'tively avoiding escape of'gase's which may be injurious; as well as avoiding con-1 sequent loss 'of efliciency .ofthe 'sintering or; roasting j a 01 gasftightr manner; .In' the arrangements illustrated Figs. 13 and 14, the'seal between thepallets and the lower wind box is airtight, andjfthej seals at the upper inner edges r of the pallet side walls maybe efi ectivej for manynses V u tz p fi afl a d constituting a 'closureat the operation.

impaired. As heretofore sealing means may be made without departing from the;

intended scope of my invention as defined in the appended f claims; v

Having thus described 'iilytnvemibn; w t 1 is;

:sinter'ing machine having pallets, imeans to pass I 7 said pallets in aipatlr in" contacting successiomeachcf ,said pallets having-at each side a seal bar and supporting meansi awind boxihoodabove said pallets having side walls extending downwardly outside vof said palletsjand along thepath thereof an airtight connection between said seal bar and said 'siderwalls and an airtight ttmneL; j a

' like chamber forming wall extendingalongandconnected r with eachside wall of the wind'box and having asliding airtight connectionwith saidpalletsfi i 2. I "a sintering'pmachinej having palletsy lmeansjfor supporting andmoving the pallets a planein eomaes a succession, glongitudinally e'xtnding coacting sealing meanscom'prising 'contactingsurfaces' on each fside of each pallet and on the supporting meansQmea'ns for-direct.

in'g agasi'stream through the pallets,;includ inga hood i dicated, various other' modifications f a of the structuresof my comb'inedup fimary and secondary r having side walls extending longitudinally along the path of movement of the pallets. and outside iof'the pallets, and means forming an elongated chamber outside of said sealing means extending along said hood and having longitudinal wall portions connected in an airtight manner h a d ad d with. gi ud nally x end ng lin means.

3. A sintering machineincluding a movable succession of receptacles, means for supporting the receptacles and for moving them, a wind box hood supported to extend over the receptacles frgm side to side and above'a'nd u inal y the eotr ean fi e i e a l en ment cooperatively between thehood and the receptac'les to resist the fiow of gasesfrom the hood between it and the sides of the receptacles, a lower wind box connected to the supporting means and in registration with the firstnamed d ox a d sealed a a n t ingress an e e of gas between it andthe moving receptacles, a second sea g means ranged-t te m a on i u lly xte ing a ber outs de of the recep a pp i me mending along and ealedto t e ead and Wind 9. and means n ma ly closing t eends o i i u na y extending chamber. I

A means for a con nuo s sintering app tu pri a se ies o Pa let ha in i u ina l extending parallel sealing surfaces and wheel supports between said surfaces at each side of each pallet, a supporting and sealing bar engaging one of the surfaces below the wheels at each side of the pallet, a wind box having side plates air-tightly connected with said seal bars, an upper seal bar and means forming tunnel-like chambers airtightly connected to the upper seal bars and the side plates of said wind box and shaped to extend outside of and around the paths of said wheels.

5. The structure defined in claim 4-in which the means for forming said tunnel-like chamber includes members at each end thereof shaped to fit the contour of said wheels and each extending longitudinally sufliciently to simultaneously embrace two wheels at each side of the pallets.

6. A sintering machine including pallets having material supporting grates, a trackway along which the pallets may be moved and longitudinally extending sealing means carried by the pallets and coacting longitudinally extending sealing strips in fixed relation to the trackway, a hood extending over the grates at each side thereof and longitudinally along the trackway and having a sealing connection with said first-mentioned sealing means, a wind box below the grates having sealing connection with the pallet coacting sealing means, and a secondary sealing means extending longitudinally of and connected to the side walls of the hood and wind box, said secondary seal being so shaped as to form a tunnel-like chamber bridging over the movable sealing and supporting means at each side of each pallet.

7. In a sintering machine, longitudinally extending pallet supporting guideways, a plurality of pallets having supporting means at the sides thereof coacting with said guideways and permitting them to be moved in succession, slidable sealing members comprising coacting longitudinal surfaces on the guideways and on each side of the pallets, a wind box below the guideways having side walls sealed to the sealing members, a wind box hood above the lower wind box and having side walls provided with sliding sealing means coacting with the moving pallets, and an additional sealing means comprising longitudinally extending wall members extending along and bridging from the upper wind box side walls to the lower wind box side walls and positioned to permit the passage therethrough of the pallet supporting means.

8. A sintering machine having guideways for support ing moving pallets, a plurality of pallets and means for moving them in succession along the said guideways, an upper wind box hood and a lower wind box below the hood and below the guideways, the pallets having surfaces coacting with the guideways and forming a seal 9. The sinteringrnachine defined in claim 8 iii-which supporting wheels are mounted at each side of the pal-f lets andinwhich the means closing the ends of the longitudinal chambers comprise longitudinally extending members having surfaces conforming to the contourof' the wheels and closely fitting thereover as they move'into and froms'aid chambers.

' 1 0. The sintering machine defined in claim 8 in which return guidewaysincluding"rails T are provided for the pallets, andthe pallets are provided with wheels at the sides'thereof adapted to run on said rails, and in which the means closing the ends" ofthe. longitudinal'c'hambe'rs, comprise spaced' fiexibl'e partitions normally meetingbut adapted to beseparated by the passage of the wheels, there being a plurality of such partition members so spaced that only one is engaged by a wheel at any one time. i

11'. In a sintering machine having pallets provided with side walls and supporting means on said side walls, means to pass the pallets in a path in contacting succession, each of said pallets having at each side thereof a seal bar slidably coacting with the supporting means, a wind box hood above the pallets and having side walls extending downwardly and outside of the side walls of the pallets, a lower wind box having its side walls airtightly connected to said seal bars, and a longitudinally extending sealing means airtightly connected to said pallet seal bar and lower wind box and to the side walls of said hood and extending outside of said pallet supporting means.

12. The structure defined in claim 11 in which the pallets are provided with wheels at the sides thereof and in which said sealing means connecting the upper and lower wind box side walls extends outside of and around the path of the wheels.

13. The sintering machine defined in claim ll in which the last-named sealing means comprises a longitudinal chamber having a plurality of flexible transverse closure members mounted within said chamber and so divided as to yield with the passing of the wheels and to close behind them.

14. The structure defined in claim 11 in which the longitudinally extending sealing means is in the form of a tunnel of non-collapsible material, and which is arranged to permit vertical movement between the inner edges of the upper and lower walls of the tunnel, said walls being airtightly connected to the sealing bars coacting with the shoulders on the pallets.

15. In a sintering machine having a plurality of pallets comprising grates and upwardly extending side walls and supporting wheels and having longitudinally extending parallel supporting and sealing shoulders at each side thereof and above and below the wheels, means for moving said pallets in a plane in contacting succession, longitudinally extending supports for the pallets having sealing surfaces engaging the supporting and sealing surface of the pallet, a wind box extending downwardly from said last-named supporting and sealing member and airtightly connected thereto, a chambered hood over the grates, a longitudinally extending sealing member between the hood and a sealing surface at each side of the pallet, an adjustable means for yieldingly supporting the weight of the hood member, said longitudinal members and shoulders constituting a primary seal between the hood and wind box and interposed pallets, secondary sealing members airtightly connected to the longitudinal sealing members and extending outwardly and around the path of the 1 of said pallet supportingrmeansfl i 7 v V 17.The structurede'fined in claim,1,6'in which the slidable sealing means between [the pallets'and the wind a V r '11 a r 1 wheels at each sidehof the pallets and forming a; chamber 1 extending along the sides of the hood. andwind box and} sealed thereto, saidchamber havingiclosure'means at- '1 i each end permitting the wheelstoenter andpas'sout wardly from the chamber while preventing ;the' free jpassage of gas, said closure nieans bein'grformed of self-sup= 'porting' yieldable materiahper'mittingrelatively vertioal adjustment of the longitudinally-extending seal bars. 16.11! a sintering maehine having pallets providedwith 7 side walls and supporting means; means'tor pass the pallets in a path in contaetingjsuccession, each-of said pal- 'lets' having at each'side'thereofra sealbarslidably coacting with the supporting means; a wind'box hood rabo ve the pallets and having sidewalls extending downwardly to the side walls of, the pallets,1slidable sealing means 7 between the wind box hood andhthe pallet sidevwall's,'a v lowefwind box aif-tightly, connected to said seal bars,

and a longitudinally extending sealing; means airtightly' V I connected to'said pallet sealrbanand lower wind box' and'to the side walls of said hood and' e xtending outside box hood is positioned at thetop of the'palletwallsl' 18, The structure defined in claim rlo in whichthe i pallets are provided withwheels at the sides thereof, and

in which said sealing means connectingthei1ppeirand 1,19'9,962-"Borson 7 1,308,864 9;, Reckard 1Iuly'8,"1 91 9," -1,491;77s= StehIi ;"A r.'22; 1924, 1,680,345 semi; Au ;1,4, 19 28 I 3 1,774,135 Fassotte =A ug. 26 ,{1930 1,810,313 Hyde J,une 16,1931 2,254,323 Shallock S'eptjZ, 1941' 2,506,569- Agnew ,May*9,;1-95,0 3

Rowen Aug 7,

heaat h he V 19. Asinte ing -xnachineihav'ing pallets 7 sidewalls, means to pass said palletslina path;seaghof said pallets'having at each side a seahbaranasuppsrt-fV ing means, a wind box hood above said pallets having side walls extending downwardly outside of saidipallet's and 7 along the path thereof,- :anairtight connection: between said sealfbar and j said hood side walls, andJtunneI-like chamber-forming wall 'structnr'es extending alongl: and

connected with the side walls'of the hobdQ and each tunnel stnicture including: aninwandly slopingr plate poslif tioned for'slidingeonnection with said pallet wall s. V 1 j T: 1' fRetel ences Cited in thefmepftni int 5 UNITED STATES PATENTS;

lower wind box side: walls extends. outside:of and. ai-c'm n'd zO ctt' 3, 1916 

